This invention relates generally to lifting devices, and more particularly, to gantry cranes for vertically raising and laterally transporting heavy objects.
Large refractory incinerators typically include a cylindrical housing having one end provided with a large access door and an opposite end provided with a smaller, vertically movable door through which waste matter can be introduced into the interior of the incinerator. Typically, a hydraulically operated ram, in conjunction with a waste receiving hopper, operates to force waste matter from the hopper through the vertically movable door and into the interior of the incinerator. Within the cylindrical housing, a plurality of generally rectangular, foraminous cast iron hearth plates from a horizontal floor onto which the waste matter is deposited for incineration. Air is introduced through passageways into the interior of the incinerator under the hearth plates to promote combustion of the refuse. Preferably, the hearth plates sealingly engage the interior of the oven and each other so that the space beneath the plates can be pressurized. Air jets are positioned in the cast iron floor and air is conveyed upwardly through the perforations in the individual cast iron plates so as to promote incineration of the burning waste matter.
Proper combustion of the waste matter, and proper operation of the incinerator, is best achieved by keeping the holes in the cast iron plates as well as the air passageways under the plates clear and clean. Because the air passageways under the plates are susceptible to being clogged with ash and other debris as the incinerator is used, special attention must be given to assuring that the cast iron plates are thoroughly cleaned when the accumulated ash is, from time to time, removed from the interior of the incinerator.
In order to assure thorough cleaning of the air passageways under the cast iron hearth plates, the plates are best removed from the interior of the incinerator during such cleaning. Heretofore, this has been performed by first threading a lifting lug into a threaded socket formed adjacent the center of each plate and thereafter manually lifting and carrying the plate from the interior of the incinerator. Because the threaded holes may not be located at the actual center of gravity of each plate, the plates can shift as they are lifted, thereby complicating their removal. Furthermore, as the cast iron plates may weigh in excess of 200 lbs. each, considerable effort and time can be expended in removing the plates and thereafter reinstalling the plates within the incinerator.
In view of the foregoing, it is a general object of the present invention to provide an apparatus for facilitating the removal and installation of cast iron hearth plates in a refractory incinerator.
It is a more specific object of the present invention to provide an apparatus for facilitating the removal and installation of cast iron hearth plates within a refractory incinerator so that the cast iron plates can be quickly and easily removed from, and reinstalled in, the incinerator with a minimum of physical effort and a maximum of safety.
It is a still more specific object of the present invention to provide an apparatus for facilitating the removal and installation of cast iron plates in a refractory incinerator wherein the apparatus can be readily adapted for use with incinerators of various sizes and shapes.